An ancient ossuary in Rouen.

A medieval church with largest and oldest collection of Renaissance frescoes in France.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

The Cimetière des Chiens et Autres Animaux Domestiques is one of the oldest pet cemeteries in the world.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

The famous winding walk at Chartres is surrounded in mystery and myth.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

Historic medieval fortified city in southwest France.

The first green space constructed on an elevated viaduct.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

A mechanized clock where a man fights off a dragon, crab, and rooster.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

The largest cemetery in Louisville is the final resting place of Col. Sanders and Muhammad Ali.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

This former tuberculosis research hospital endeavored to cure the dreaded disease with fresh air and positive attitudes.

A once-booming Mississippi River town with a history of racial violence is now eerie and mostly abandoned.

An abandoned vacation home spent a decade taking on legends. It's now taking on water.

The world's most active stratovolcano is almost always erupting.

The largest earthwork effigy in the world.

Speak to a companion on the other side of the room loud and clear through this architectural anomaly.

Less a museum than a bizarre fantasy world created by artists and engineers.